Upright extraction cleaning machine with unitary accessory hose duct

ABSTRACT

An extraction cleaning apparatus including a base housing, a fluid recovery system including a tank having a fluid recovery chamber for holding recovered fluid, a working air conduit, an above floor accessory hose mounted at one end to the housing for optional above floor cleaning, and a unitary duct mounted to the housing and connected at a first end to the accessory hose one end and, at another end, connected to the working air conduit at an accessory hose inlet a conversion valve in the working air conduit between the suction nozzle and the accessory hose inlet to selectively connect the vacuum source to either the suction nozzle or to the accessory hose. Portions of the unitary duct are flat and an intermediate portion of the unitary duct extends beneath the recovery tank.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 09/753,349, filed Jan. 2, 2001, now U.S. Pat. No. 6,412,141which is a continuation of U.S. patent application Ser. No. 09/112,527filed Jul. 8, 1998, now U.S. Pat. No. 6,167,587 which claims the benefitof U.S. Provisional Application Ser. No. 60/075,924, filed on Feb. 25,1998, and U.S. Provisional Application Ser. No. 60/052,021, filed onJul. 9, 1997.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an extraction cleaning machine and, moreparticularly, to an upright extraction cleaning machine.

2. Description of Related Art

Upright extraction cleaning machines have been used for removing dirtfrom surfaces such as carpeting, upholstery, drapes and the like. Theknown extraction cleaning machines can be in the form of a canister-typeunit as disclosed in U.S. Pat. No. 5,237,720 to Blase et al. or anupright unit as disclosed in U.S. Pat. No. 5,500,977 to McAllise et al.and U.S. Pat. No. 4,559,665 to Fitzwater.

Current upright extraction cleaning machines can be made easier to useby limiting the weight and number of components, such as fluid storagetanks, on the pivoting handle of the upright cleaning machine. Reducingthe weight that a user must support as the handle is tilted rearwardlycan also lower the center of gravity for the machine, which results in abetter feel to the user.

Furthermore, the current extraction cleaning machines can be made easierto use and better adapted for a variety of cleaning conditions. Forexample, none of the current extraction cleaning machines includes anelevator responsive-to-handle position for restraining a floatingroller-type agitation brush, which is automatically height adjustable inresponse to changes on the surface being cleaned. Another probleminherent with the known extraction cleaning machines is the difficultyof filling and emptying the fluid supply chamber and fluid recoverychamber, particularly with bladder-within-a-tank type assemblies.Further, none of the current upright extraction cleaning machines aresimply convertible to a pre-spray applicator for directing cleaningsolution to and agitating the surface to be cleaned without applyingsuction. Finally, current extraction cleaning machines do not use a thesame motor to drive an agitation brush as well as an impeller. Is somecases a separate motor is used. In other cases, a turbine is used todrive the agitation brush or brushes which diminishes the suction poweravailable to extract the dirty solution from the floor surface.

A more recent development in the extraction cleaning industry is the useof steam or hot water as a cleaning agent. The cleaning machineincorporates a boiler or other means for generating steam or hot water,which is pumped to an applicator where it is brought into contact withthe surface being cleaned. Because the steam is airborne, it may beunsafe to include detergents and the like in the cleaning solution.Further, while the steam systems have the advantage of creating atemperature that effectively kills a wider range of microbes, bacteria,microorganisms, and mites, the steam systems generally suffer from poorcleaning performance. Additionally, the high power requirement forgenerating steam may not be sufficient with ordinary 120V power suppliesfor running a vacuum motor as well as the steam generator, so cleaningperformance is further hindered. Also, by adding a heater to a fluidsupply chamber, the user may be inconvenienced by the amount of timerequired to heat the contents of the supply chamber to the desiredtemperature. Conversely, conventional detergent cleaning systems aresomewhat effective at cleaning surfaces, but could be made moreeffective by raising the temperature of the cleaning solution to sometemperature below the boiling point. There is an optimal temperature atwhich cleaning performance is maximized without causing damage tocarpets or, setting stains. This temperature is around 150° Fahrenheit.

SUMMARY

According to the invention, a portable surface cleaning apparatuscomprises a housing adapted for movement along a surface to be cleaned,a liquid dispensing system and a liquid recovery system. The liquiddispensing system includes a liquid dispenser mounted to the housing forapplying liquid to a surface to be cleaned, a liquid supply tank forholding a supply of cleaning liquid and a liquid supply conduit fluidlyconnected to the liquid supply tank and to the dispenser for supplyingliquid to the dispenser. The liquid recovery system comprises a recoverytank removably mounted on the housing and having a liquid recoverychamber for holding recovered liquid, a suction nozzle associated withthe housing adapted to draw dirty liquid from the surface to be cleaned,a working air conduit extending between the recovery chamber and thesuction nozzle and a vacuum source in fluid communication with therecovery chamber for generating a flow of working air from the nozzlethrough the working air conduit and through the recovery chamber tothereby draw dirty liquid from the surface to be cleaned through thenozzle and working air conduit and into the recovery chamber to therebyrecover dirty liquid from the surface to be cleaned.

In accordance with one embodiment of the invention, an accessory hose ismounted at one end to the housing for option above floor cleaning; aunitary duct is connected at a first end to the accessory hose one endand at another end, is connected to the working air conduit at anaccessory hose inlet; and a conversion valve is mounted in the workingair conduit between the suction nozzle and the accessory hose inlet toselectively connect the vacuum source to either the suction nozzle or tothe accessory hose.

In one embodiment, portions of the unitary duct are flat. In a preferredembodiment of the invention, at least one of upper and lower portions ofthe unitary duct is flat. Further, an intermediate portion of theunitary duct extends beneath the recovery tank.

In another embodiment, the housing includes a base housing and anupright handle, and the upright handle is pivotally mounted to the basehousing. Further, the recovery tank is removably mounted in the basehousing. In addition, the accessory hose is mounted at the one end to arear portion of the base horsing.

In accordance with one embodiment of the invention, a fluid passagewayis provided between the fluid supply chamber and the recovery chamber ofthe tank, whereby the tank is in fluid communication with the fluidsupply chamber and the pressure in the flexible bladder is equalizedwith the pressure in the tank as the cleaning fluid is dispensed and thedirty liquid is collected in the tank. The flexible bladder preferablyincludes an outlet opening in the bottom portion thereof connected tothe fluid supply conduit. In one embodiment, the flexible bladderextends between a bottom surface of the tank and an upper portion of thetank.

In a preferred embodiment, the fluid passageway between the fluid supplychamber and the recovery chamber of the tank comprises a filling spoutdisposed in an upper portion of the flexible bladder. A baffle plate ismounted within the upper portion of the tank and includes an opening.The filling spout on the flexible bladder extends through the opening inthe baffle plate and is supported thereby. Preferably, the tank includesa removable lid on a top portion thereof and a filling spout is disposedbetween the baffle plate and the lid.

Further according to the invention, in one embodiment, the tank has anoutlet opening in a bottom portion thereof and a drain plug is removablymounted in the outlet opening.

In another embodiment, a lid mounted on the tank defines an expansionchamber having an inlet opening and an outlet passage between theexpansion chamber and the tank. The working air conduit is connected tothe lid inlet opening so that the working air is drawn through theexpansion chamber in the lid and into the tank. A first diverter bafflein the expansion chamber reverses the direction of flow of the workingair between the inlet opening and the outlet passage. A second diverterbaffle in the outlet passage reverses the direction of flow of theworking air between the expansion chamber and the tank. Thus, theworking air flow reverses direction twice between the inlet opening ofthe expansion chamber and the tank. The lid is preferably removablymounted to the tank. In one embodiment, the outlet passage extendsbeneath the expansion chamber and includes an outlet opening and thefilling spout in the flexible bladder includes an opening beneath thelid and substantially above the outlet opening in the outlet passage.Further, the filling spout is disposed between the baffle plate and thelid and the lid includes a shroud extending downwardly from the bottomsurface thereof surrounding the filling spout to a point below theopening of the filling spout. Preferably, the shroud extends beneath theoutlet opening of the outlet passage.

In another embodiment, the working air conduit includes a conversionvalve for selectively opening and closing fluid communication betweenthe tank and the suction nozzle. A manual actuator knob is connected tothe conversion valve for movement between first and second positions andthereby selectively moving the conversion valve between open and closedpositions. According to the invention, an over-center linkage mechanismis connected to the manual actual knob to bias the conversion valve tothe open and closed positions. In a preferred embodiment, theover-center linkage mechanism comprises a spring-biased plunger assemblymounted to the actuator knob for movement therewith. The actuator knobis preferably mounted to the base module for rotational movement betweenthe first and second positions and the spring-biased plunger assembly ismounted to the actuator knob for rotational movement therewith. In apreferred embodiment, the conversion valve is pivotably mounted to thebase for rotational movement between the open and closed positions andthe conversion valve includes an arm having a distal end extending tothe plunger assembly and rotatably connected thereto. The rotationalmotion of the actuator knob is translated to rotational movement of theconversion valve through the arm.

In yet another embodiment, a flow indicator is mounted to the basemodule and has a visibility window observable to a user and the flowindicator is disposed in the fluid supply conduit and is responsive tothe flow of fluid through the fluid supply conduit to visually indicatethe flow of fluid through the supply conduit to the user. In a preferredembodiment, the flow indicator comprises an impeller rotatably mountedin a flow indicator housing and driven by the fluid flowing through theflow indicator.

In still another embodiment of the invention, a fluid supply conduit inthe liquid dispensing system includes a pump fluidly connected to thefluid supply chamber and to the dispensing nozzle for supplying cleaningfluid to the dispensing nozzle. A pump primer is connected to the pumpfor priming the pump and includes a valved opening connected to thevacuum source. According to the invention, the pump primer includes ahousing defining a priming chamber with an inlet opening connected tothe fluid supply chamber and an outlet opening connected to an inlet forthe pump. In a preferred embodiment of the invention, the valved openingis in an upper portion of the priming chamber. Further, the pump primerincludes a valve chamber and a plunger chamber. The valve chamber has aninlet opening defined by the valved opening in the primer chamber and anoutlet opening defining an inlet opening to the plunger chamber. Theplunger chamber has an outlet opening in fluid communication with thevacuum source. A buoyant plunger is reciprocally mounted in the plungerchamber for generally vertical movement therein. A valve is mounted inthe valve chamber and reciprocally movable between the inlet opening andthe outlet opening thereof and connected to the plunger for movementtherewith. By this structure, the valve closes the outlet opening to thevalve chamber when fluid in the plunger chamber raises the plunger andthe valve closes the inlet opening when fluid in the plunger chamberfalls to a predetermined level. In a preferred embodiment of theinvention, the valve in the valve chamber is an umbrella valve.

In a further embodiment of the invention, the surface cleaning apparatusincludes a fluid supply conduit including a pump fluidly connected tothe fluid supply chamber and to the dispensing nozzle for supplyingcleaning fluid to the dispensing nozzle. The pump has a drive shaft fordriving the pump. An agitation brush is mounted in the forward portionof the base module. A motor is mounted in the base housing and has amotor drive shaft connected to the agitation brush for rotatably drivingthe agitation brush. According to the invention, a first mechanicalconnector extends between the motor drive shaft and the pump driveshaft, whereby the motor drives both the agitation brush and the pump.In a preferred embodiment of the invention, the motor drive shaft isconnected to the agitation brush through a second mechanical connectorbetween the pump drive shaft and the agitation brush. The pump driveshaft has a mechanical step-down device connecting the drive shaft tothe first mechanical connector to step down the speed of rotation of themotor shaft in the pump drive shaft. Preferably, the first and secondmechanical connectors are belts, with the second connector preferablybeing a timing belt and the first connector preferably being a stretchbelt. Typically, the stretch belt rides directly on the motor driveshaft. In a preferred embodiment of the invention, inner and outerpulleys are mounted in axially spaced relationship on the pump shaft,wherein the timing belt is reeved around the outer pulley and thestretch belt is reeved around the inner pulley. Further, there is abaffle between the inner and outer pulleys to minimize liquid transferbetween the inner and outer pulleys. The inner and outer pulleys arepreferably of a size to step down the speed of rotation of the motorshaft at the pump drive shaft and at the agitation brush. Furtheraccording to the invention, the base module includes a housing with anopening adjacent to the first mechanical connector and a removable dooris selectively mounted to the housing to cover the opening. Preferably,the removable door includes a flange and the housing includes a grooveand the flange is slidably received in the groove to at least partiallysupport the door in the opening. The housing preferably includes asecond removable door which forms a portion of the baffle between theinner and outer pulleys.

Further according to the invention, the base module includes an upperhousing portion and a lower housing portion and an upright handle ispivotably mounted to the rear portion of the base module through atleast one bearing for rotatable reception in the housing. According tothe invention, a socket is formed between the upper and lower housingportions for rotatably receiving the bearing. Preferably, the bearing isformed integral with the lower portion of the upright handle. Desirably,the socket is formed by arcuate surfaces in mated edges of the upper andlower housing portions. The lower portion of the upright handle includesdiverging arms, each including a bearing. Each bearing is formedintegral with the lower portion of the upright handle. Typically, wheelsare mounted to an axle which are received within the bearings forrotationally mounting the wheels to the handle.

In accordance with another embodiment of the invention, a portablesurface cleaning apparatus has a base module with a brush assemblyhaving an agitation brush generally disposed in the front portion of thebase module and a pivot arm for pivotably supporting the agitation brushrelative to the base module. A first end of the pivot arm is mounted tothe agitation brush for rotation of the agitation brush with respect tothe pivot arm and a second end of the pivot arm is pivotably mounted tothe base module, whereby the brush assembly is free-floating to adjustto different surface heights. According to the invention, an elevatorassembly is reciprocally mounted to the base module and movable inresponse to movement of the upright handle from an operative position tothe upright position. The elevator assembly includes an arm disposed atone end adjacent the pivot arm and having a lifting surface for upwardlypivoting the pivot arm and a second end extending toward the handle andhaving a contacting surface for sliding along the outer surface of thelower portion of the handle. Movement of the arm toward the frontportion of the base module by pivoting the upright handle to the storageposition is translated into movement of the agitation brush away fromthe surface to be cleaned. Preferably, a spring biases the arm towardthe handle.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described with reference to the drawingswherein:

FIG. 1 is a perspective view of the extraction cleaning machineaccording to the invention;

FIG. 2 is an exploded view of a base module of the extraction cleaningmachine shown in FIG. 1;

FIG. 3 is an exploded view of a base module and tank assembly of theextraction cleaning machine of FIG. 1;

FIG. 4 is an exploded view of a handle assembly and portions of the basemodule for the extraction cleaning machine of FIG. 1;

FIG. 5 is a partial sectional side view of the foot module of theextraction cleaning machine of FIG. 1;

FIG. 5A is an exploded view of a floating brush assembly for theextraction cleaning machine of FIG. 1;

FIG. 5B is a perspective view of an alternative brush assembly for theextraction cleaning machine of FIG. 1;

FIG. 6 is a partial sectional side view of the extraction cleaningmachine of FIG. 1 with the handle assembly in a tilted position;

FIG. 7 is a side sectional view of the pump and pump priming assembly ofthe extraction cleaning machine of FIG. 1 with a plunger in a firstposition;

FIG. 8 is a side sectional view of the pump and pump priming assembly ofthe extraction cleaning machine of FIG. 1 with a plunger in a secondposition;

FIG. 9 is a partial perspective view of the belt access door assembly ofthe extraction cleaning machine of FIG. 1;

FIG. 10 is a partial sectional view of the auto-mix valve of theextraction cleaning machine of FIG. 1 with a valve stem in a firstposition;

FIG. 11 is a partial view of the auto-mix valve of the extractioncleaning machine of FIG. 1 with a valve stem in a second position;

FIG. 12 is a partial side sectional view of a diverter valve with thevalve plate shown in a first position and in phantom for a secondposition for the extraction cleaning machine of FIG. 1;

FIG. 13 is a partial side view of the valve assembly of FIG. 12 with thevalve plate in the second position;

FIG. 14 is a sectional view of the air/water separator lid along line14—14 of FIG. 3;

FIG. 14A is a partial side view of a closure plate in three positionsrelative an air exit from the air/water separator lid of FIGS. 13 and14;

FIG. 14B is a partial sectional view taken along lines 14B—14B of FIG.14;

FIG. 15 is a sectional view of the air/water separator lid along line15—15 of FIG. 14;

FIG. 16 is a partial sectional view of the tank assembly and handleassembly of the extraction cleaning machine shown in FIG. 1;

FIG. 17 is a fluid flow diagram for the extraction cleaning machine ofFIG. 1;

FIG. 18 is an exploded view of the in-line heater of the extractioncleaning machine of FIG. 1;

FIG. 19 is a top view of the fluid flow indicator of the extractioncleaning machine of FIG. 1;

FIG. 20 is a side sectional view of the fluid flow indicator of FIG. 19;

FIG. 21 is a bottom perspective view of a drain plug of the base moduleand tank assembly of FIG. 3; and

FIG. 22 is a top perspective view of the drain plug of the base moduleand tank assembly of FIG. 3 and illustrated in FIG. 22.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings and to FIG. 1 in particular, an uprightextraction cleaning machine 12 according to the invention is shown. Themachine 12 is a portable surface cleaning apparatus including a basemodule 14 adapted to roll across a surface to be cleaned and an uprighthandle assembly 16 pivotably mounted to a rear portion of the basemodule 14.

As best shown in FIGS. 1-3, the base module 14 includes a lower housingportion 15 and an upper housing portion 17, which together define aninterior for housing components and a well 730 for receiving a tankassembly 50. Further, a well 732 in the upper housing portion 17receives a detergent supply tank 870, as best shown in FIG. 3. The upperhousing portion 17 receives a transparent facing 19 for defining a firstworking air conduit 704 and a suction nozzle 34, which is disposed at afront portion of the base module 14 adjacent the surface being cleanedfor recovering fluid therefrom. The handle assembly 16 has a closed loopgrip 18 provided at the uppermost portion thereof and a combination hoseand cord wrap 20 that is adapted to support an accessory hose 22 and aelectrical cord (not shown) when either is not in use. A latch assembly21 is pivotably mounted to the rear portion of the base module 14adjacent the rotational union of the handle assembly 16 therewith forreleasably locking the handle assembly 16 in its upright position.

As shown in FIG. 2, the base module 14 houses a drive motor 196 that isconnected to a source of electricity by the electrical cord. A motorcompartment 500 within the base module 14 is a clamshell-shaped housingfor holding a motor assembly in place and preventing rotation thereofThe clamshell motor compartment 500 includes an upper half 502 and alower half 504. The upper half 502 is removable from the lower half 504,which is integral to the extraction cleaner base module 14. Thus, abottom wall of the lower half 504 is the bottom surface of theextraction cleaner base module 14. An arm 651 extends upwardly from themotor housing 500 in the base module 14 to support the flow indicator650, which is mounted to an upper end thereof. An opening 653 in theupper housing portion 17 receives the flow indicator 650 when thatportion is mounted to the lower housing portion 15.

The motor compartment 500 includes a large circular impeller fan housing510 and a smaller motor housing 512, further having a generally T-shapedcross section. The impeller fan housing 510 surrounds an inner housing41 defining a vacuum source 40, As shown in FIG. 2, the accessory hoseintake duct 540 as flat upper and lower portions and is unitary inconstruction. Which is created preferably by an impeller (not shown)disposed within the housing 41. The housing 41 includes a large aperture516 for mounting a vacuum intake duct 530, which is sealed to theaperture 516 by a gasket 520. The vacuum intake duct 530 connects thevacuum source 40 to an air/water separation chamber 750 (shown in FIGS.3, 14, 14A, 14B and 15) in a lid 700 on the tank assembly 50, as well asthe suction nozzle 34 on the front portion of the base module 14 and asuction nozzle (not shown) on a distal end of the accessory hose 22. Thesmaller end 512 includes a small aperture 524 for receiving therethrougha motor drive shaft 198. A stretch belt 204 is received on the motordrive shaft 198 outside of the clamshell motor compartment 500. Further,an upper surface 520 of the motor compartment 500 supports and securesan accessory hose intake duct 540 partially defining a second workingair conduit 706 (as shown best in FIGS. 12-14), which connects thesuction nozzle on the distal end of the accessory hose 22 to the vacuumsource 40.

The drive shaft 198 of the drive motor 196 is connected to an interimdrive shaft 200 of a solution pump 202 by the stretch belt 204, which inturn, is connected to a rotatably mounted agitation brush 206 by atiming belt 208, as best illustrated in FIGS. 5 and 6. On the oppositeside of the motor 196, the motor drive shaft 198 supports the impeller(not shown) within the impeller housing 41, which provides the vacuumsource 40 and is mounted inside the housing 510 of the motor compartment500. With this configuration, a single drive motor 196 is adapted toprovide driving force for the impeller, the solution pump 202, and theagitation brush 206.

As best seen in FIGS. 2, 5, 5A, and 6, the rotatably mounted agitationbrush 206 is adapted for floor-responsive adjustment by a floating brushassembly 400 mounted within an agitation brush housing 26 disposedwithin a forward portion of the base module 14. The floating movement ofthe agitation brush 206 is a horizontally oriented arcuate path forreciprocation toward and outward of the agitation brush housing 26. Ends452 of an agitation brush shaft 206 are received in bearings 454, whichin turn, are press fit into inwardly extending bosses 456 to provide apair of opposed articulating arm members 458. Alternatively, stub shafts(not shown) can extend from the arm members 458 and the ends 452 can bereplaced with bearings similar to 454 for rotational installation of thebrush 206 on the arm members 458.

Each arm member 458 comprises a back plate 460 with a pivot pin 462provided at the rear of the plate 460. In addition, a laterallyextending belt guard 466 is preferably integrally formed with thearticulating arm 458. The belt guard 466, which extends laterallyinwardly enough to cover the timing belt 208, minimizes the lodging ofthreads and other foreign material in the timing belt 208 and protectsthe carpet or other surface positioned below the base assembly 14 fromthe rotating belt 208.

As best shown in FIGS. 5-6, 9, the timing belt 208 is reeved through apulley 216 mounted at one end of the brush 206 and a pulley 222 on theinterim drive shaft 200 of the pump 202, which includes a separatepulley 220 through which is reeved the stretch belt 204, which, in turn,extends around the drive shaft 198 of the motor 196. As best shown inFIGS. 7 and 9, the radius of the pulley 220 is larger than the radius ofthe pulley 222. Further, the pulley 220 has a convex cross section ofits periphery, whereby it is adapted to receive the smooth stretch belt204, while the pulley 222 has a toothed perimeter adapted forregistration with the teeth in the timing belt 208.

The pivot pins 462 of the arm member 458 are rotatably supported securedin a bearing (not shown) mount integrally formed with an internal wallof the agitation brush housing 26. Further, the pivot pins 462 are heldin the bearing by a support 478 on the non-belt side of the base module14 and the an arm 258 of the second belt access door 252 on the beltside of the base module, as best shown in FIG. 5A. Both the arm 258 andsupport 478 are secured to the agitation brush housing 26 by aconventional fastener (not shown) inserted through an aperture in eachpart. The arm members 458 are preferably limited in their downwardmovement relative to the agitation brush housing 26 by the length of thetiming belt 208 as well as the engagement of the brush guards 466 withthe arm 258 and the support 478. As the floating brush assembly 400extends further and further downwardly, the belt 208 will stretch andresist further downward movement. Eventually, the brush guards 466 oneach arm 458 will contact respectively the arm 258 and the support 478,which prevents any further downward movement.

With this floating agitation brush assembly 400, the cleaning machine 12according to the invention can almost instantaneously adapt to varyingcarpet naps or other inconsistencies on the surface being cleaned. Thearm members 458 also allow the rotating brush 206 to drop below thenormal floor plane, as shown in FIG. 6, to, for example, provide contactwith a bare floor.

As an alternative to the floating, rotatably mounted agitation brush206, a floating strip agitation brush 224 could be incorporated into thecleaning machine 12, as seen in FIG. 5B. In this embodiment, the stripbrush 224 comprises a linear brush portion 492 with bristles 494extending downwardly therefrom, and a pair of integrally molded arms 496having pivot pins 502, which can mount to the arm members 458 in placeof the pivot pins 462 supporting the agitation brush 206. With thisstructure, the strip brush 224 can move vertically in response tochanges to the carpet nap or other inconsistencies in the floor beingcleaned.

As shown in FIGS. 2, 5 and 6, an elevator assembly 410 comprises acentral support member 412 having at one end an L-shaped actuating arm418, and at another end, the ramped surface 414 on a forward arm 404opposed by a guide 416. Between the guide 416 and the ramped surface 414is mounted a spring assembly 406, which biases the assembly 410 rearwardtoward the handle assembly 16. The spring assembly 406 includes a spring436; a stop 426, which is attached to the base module 14 and throughwhich the forward arm 404 travels; and a flange 428, which is integralwith the forward arm 404. The spring 436 is held between the flange 428and stop 426, and biases the assembly 410 rearward relative the stop 426through force on the flange 428.

The arm 418 extends from within the base module 14 where it is mounted,through an aperture 402, towards the handle assembly 16. The actuatingarm 418 is forced horizontally forward when the rotatably mounted handle16 on the base module 14 is put in the upright position, which forces anupper portion 422 of the actuating arm 418 in a horizontal and forwarddirection. More specifically, as shown in FIG. 5, a curved surface 424on the handle assembly 16 strikes a rounded distal end 420 of theL-shaped actuating arm 418 when the handle assembly 16 is put in itsstorage or non-use position. When the handle assembly 16 is pivotedrearwardly for use, as shown in FIG. 6, the curved surface 424 shiftsrearwardly and the spring-biased elevator assembly 410 follows, with end420 riding the curved surface 424, until the elevator assembly 410reaches a rearward, rest position.

Thus, forward movement of the actuating arm 418 forces the supportmember 410 and ramped surface 414 forward, wherein the ramped surface414 contacts the underside of the brush guards 466 on each arm 458,thereby raising the floating brush assembly 400 as the elevator assembly410 moves from a rearward position to a forward position in the basemodule 14. That is, as the ramped surface 414 moves towards the front ofthe base module 14, the agitation brush assembly 400 slowly rises as thebrush guards 466 ride the ramped surfaces 414. Such a constructioneliminates the need for a manual arm for lowering and raising theagitation brush assembly 400 for storage or use of the accessory hose22, thereby eliminating risks of damage to the brush assembly andprotecting the carpet from the agitation brush assembly 400 restingthereon. When the handle 16 is moved to the in-use position, the springassembly biases the elevator assembly to its normal, rearward position.

As seen best in FIGS. 1 and 4, the base module 14 is supported at therear portion thereof by a pair of opposed rear wheels 552. The handleassembly 16 includes a U-shaped lower portion 560 having opposed arms562 and 564 including cylindrical bearings 578 for mounting the handleassembly 16 to the base module 14 and supporting axles 554 on a commonaxis for rotatably mounting the wheels 552 to the extraction cleanerbase module 14. More particularly, the handle assembly 16 tapers fromits wide, lower portion 560 to a thinner handle portion 570, having athin handgrip portion 572, including the closed loop grip 18 at itsuppermost end, by which the user moves the extraction cleaner. Thebearing 578 include a central circumferential groove 576 for receivingarcuate portions 588, 589 of the base module 14 whereby rotation of thehandle assembly 16 is facilitated.

The handle assembly 16 further comprises a front portion 580 and a rearportion 582 defining a substantially hollow interior supported bymultiple ribs 558. Mounts 584, disposed radially on the interior of thefront and rear portions 580 and 582 support an in-line heater 54, aswill be described in detail below. The substantially flat front portion580 is secured to the mated rear portion 582 by conventional fasteners,such as screws. The rear portion 582 further includes the combinedaccessory hose and electrical cord mount 20.

Returning to the lower portion 560, the arms 562, 564 comprise portionsof both the front portion 580 and the rear portion 582. When theassembly 16 is secured together, these arms 562, 564 pivot about thebearing 578 integrally formed with the arms 562, 564. The bearings 578,in turn, receive axles 554, on each side, respectively, for mountingwheels 552. The axles 554 extend through the wheels 552, apertures 586through the rear portion 582 of the lower arms 562, 564, and thebearings 578 integrally formed with the arms 562, 564. The axles 554,556 are secured by large diameter axle mounting clips 594, disposed,when installed, adjacent the bearings 578 and within the base module 14.A side edge 598 of the extraction cleaner base module 14 includes anarcuate surface 588 to accommodate the handle bearings 578 secured oninside portions of each arm 562, 564 of the rear portion 582.

Once the handle assembly 16 is mounted to each base module 14, with theaxles 554 secured by the mounting clips 594, the extraction cleanerupper housing portion 17 is secured to the lower housing portion 15. Theupper housing portion 17 also has an arcuate surface 589 formed in aside thereof for accommodating and securing the integral bearings 578 ofthe arms 562, 564. More specifically, the arcuate surfaces 588, 589 ofthe side walls of the housings 15, 17 are received in the centralcircumferential groove 576 formed in the circumference of each integralbearing 578. Thus, when the base module 14 is formed of the housings 15,17, the bearings 578 of the arms 562 are secured therebetween such thatthey can only rotate between an upright, stored position and an in-useposition and the wheels are mounted to axles 554,556 received throughapertures in the bearings 578 and secured by mounting clips 594.

The concentric wheel axle and handle pivot transfers all the force onthe handle assembly 16 to the wheels 552 to keep downward force on thesuction nozzle 34 constant. Further, the tank assembly 50, as shown inFIG. 3, center of gravity is close to the wheel center so that changingtank volume does not alter the downward force on the suction nozzle 34and allows the weight of the tank assembly 50 to be carried on thewheels 552 fairly evenly. Also, the handle assembly 16 supports verylittle weight and therefore keeps the weight that the user feels throughthe handle assembly 16 to a minimum. This creates an upright extractioncleaning machine 12 that is easy to use and less tiring for theoperator.

The handle assembly 16 is releasably locked against rotation from itsupright position by a latch assembly 21, which is pivotably mounted tothe rear portion of the base module 14 adjacent the rotational union oflower leg 564. The latch assembly 21 includes an upright lower portionwhich is pivotally mounted to the base module 14 at a rear cornerthereof and an upper portion which extends upwardly and rearwardly ofthe lower portion. A molded-in spring arm extends rearwardly from thelower portion of the latch assembly 21 and bears against a rear portionof the base module 14 to bias the lower portion forwardly and againstthe rear portion of the lower leg 564. The upper end of the lowerportion of the latch assembly 21 forms a horizontal latching surfacewhich bears against the rear portion of the lower leg 564 and engagesprojections thereon to lock the handle in the upright position in aconventional fashion. Thus, as the handle assembly 16 is pivotedupright, the rear portion of the lower leg 564 rides along thehorizontal latching surface until the edge catches the projection on therear portion of the lower leg 564, at which point the handle assembly 16is locked upwardly. To release the latch assembly 21, the user pushesthe step downwardly and against the bias of the molded-in spring torelease the horizontal latching surface from the projection. Thelatching mechanism is conventional and forms no part of the invention ofthis application. Any conventional latching mechanism can be used withthe handle and base module in the invention.

The tank assembly 50 is removably supported on the rear of the basemodule 14. An air/water separator lid 700 seals the top of the tankassembly 50, which includes a valve mechanism 80 on a bottom portion forcontrolling the flow of cleaning solution fluid from the fluid supplychamber 49. The base module 14 includes a valve seat 88 complementary tothe valve mechanism 80, and the bottom portion of the tank assembly 50and the valve seat 88 are substantially complementary to one another sothat the upwardly extending valve seat 88 is substantially surrounded byand received in the bottom of the tank assembly, as will be describedfurther below.

The lid 700 is secured to the tank assembly 50 by a rotatable handle790, as best shown in FIG. 16, which can be moved between a storageposition, in which the tank 50 is sealed by the lid 700 and the handle790 is disposed rearwardly horizontal (as shown in solid lines); atransport position, in which the tank 50 is sealed and the handle 790extends vertically upward (shown in phantom lines) for ease in carryingby the user; and a service position, in which the lid 700 can be removedfrom the tank assembly 50 and the handle 790 is disposed forwardly at anacute angle relative the lid (shown in dashed lines). The U-shaped tankhandle 790 rotates about a pivot 792 projecting from a side of the lid700. The pivot 792 is received in a bushing 794 disposed centrally in acircular mounting portion 796 at the ends of the handle 790. An arcuatewall 798 extending transversely from the mounting portion 796, integraltherewith, and having an opening 788 surrounds the bushing 794. When thehandle 790 is rotated about the pivot on the lid, an inside surface 784of the wall 798 engages a tab 786 extending transversely from an upperlip 782 of the tank assembly 50 for locking the lid 700 to the tankassembly. The surface 784 of the wall 798 engages the tab 786 when thehandle 790 is in either the storage or transport position. When in theservice position, the tab 786 is aligned with the opening 788 in thewall 798, whereupon the lid 700 can be removed from the tank assembly50.

As best shown in FIGS. 3, 14, 15, a flexible bladder 120, which is usedas a clean water reservoir, is mounted inside a rigid tank assembly 50.Thus, the tank assembly 50 is divided into two fluid chambers by thebladder 120; a fluid supply chamber 49, comprising the interior of thebladder 120, and a fluid recovery chamber 48, comprising the volumebetween the flexible bladder 120 and the rigid walls of the tank housing46. The bladder 120 is molded from a pliable thermoplastic material andis collapsible when empty to accommodate recovered fluid in the volumebetween the bladder 120 and the tank housing 46. Initially, the bladder120 is full of water or cleaning solution and occupies the vast majorityof the volume within the tank housing 46. As the user sprays thecleaning solution onto the surface to be cleaned, the volume of fluid inthe bladder 120 is reduced corresponding to the volume of solutionsprayed on the surface. During suction, recovered dirt and water arereceived in the tank housing 46 in the volume between the bladder 120and the tank housing 46. The volume available in the bladder 120 due toapplication of the cleaning solution is made available to recoveredfluid by the pressure of the recovered fluid collapsing the bladder 120,thereby forcing air out of the bladder 120. Because recovery of the usedcleaning solution is always less than 100% of the solution applied,there will always be ample room inside the tank housing 46 once thecleaning solution has been applied to the surface.

The bladder 120 is disposed within the tank assembly 50 between a bottomsurface 860 of the rigid tank housing 46 and a snap-in baffle plate 800,which will be explained in further detail below. An aperture 824 in thebaffle plate 800 has a diameter approximately matching that of a smalldiameter end 125 of a funnel-shaped filling spout 124 of the bladder120. Further, an upstanding collar 828 surrounds the aperture 824. Acylindrical shroud 770, as best shown in FIG. 17, is mounted on theinside of the air/water separator lid 700 and extends downwardlytherefrom to capture the filling spout 124. Thus, the increasingdiameter outside surface of the funnel-shaped filling spout 124 isretained in the aperture 824 and supported by the collar 828, therebyholding the flexible bladder 120 in an upright position in the tankhousing 46 between the bottom surface 860 and the baffle plate 800therein. As space between the upstanding collar 828 and the downwardlyextending shroud 770 defines a fluid passageway between the fluid supplychamber 49 and the recovery chamber 48, whereby the fluid supply chamber49 and the recovery chamber 48 maintain the same pressure, negative orotherwise.

The flexible bladder 120 includes an outlet 130 disposed in a lowercorner of the flexible bladder 120. The outlet 130 is mated with anoutlet aperture 862, as best viewed in FIG. 16, in the bottom surface860 of the rigid outer shell for supplying fluid to a fluid applicationsystem 950 and securing the bladder 120 to the rigid bottom surface 860of the tank housing 46.

The funnel-shaped filling spout 124 of the bladder 120 facilitatesfilling the bladder 120 and equalizing air pressure between the fluidsupply chamber 49 and recovery chamber 48. The filling spout 124 isalways open, so as to vent air from the bladder 120 as it collapses involume and the usable volume within the rigid outer walls of the tankhousing 46 expands in volume. Further, the open filling spout 124ensures that both chambers 48, 49 are at substantially the sameatmospheric pressure, which is preferably negative relative to standardatmospheric pressure because of the communication of the vacuum source40 to the tank assembly 50 via the air/water separator lid 700, as willbe explained further below. The volume of the bladder 120 is preferablyone gallon.

As best shown in FIG. 17, the valve mechanism 80 is provided within theoutlet aperture 862 through the bottom surface 860 of the tank housing46 and the aligned outlet 130 in the bladder 120 for controlling theflow of cleaning solution fluid from the fluid supply chamber 49. Thevalve mechanism 80 comprises a valve member (not shown) mounted withinthe aligned aperture 862 and outlet 130, which together are selectivelycovered by the valve member to enable or prevent the flow of fluid tothe fluid application system 950.

The base module 14 includes a valve seat 88, shown best in FIG. 17, thathas a fluid reservoir 90 adapted to receive fluid through the fluidaperture 862 and conduct this fluid to one end of the conduit 140, theother end being mounted to a clean water inlet 332 of a mixing valveassembly 310. The bottom wall 860 of the tank housing 46 and the valveseat 88 are substantially complementary to one another so that theupwardly extending valve seat 88 is substantially surrounded by andreceived in the bottom wall 860. A projection 94 is provided in thefluid reservoir 90 and is adapted to contact a head of a shaft of thevalve member (not shown). A spring received on the shaft of the valvemember is adapted to bias the valve member into the closed positionthereby preventing the flow of fluid through the fluid apertures. Whenthe tank housing 46 is seated on the base module 14, the head of thevalve member contacts the projection 94 and deflects the valve upwardlythereby permitting the flow of fluid around the valve, through the fluidapertures into the fluid reservoir 90 of the valve seat 88, and to thefluid application system 950. A gasket 81 seals the junction between thevalve mechanism 80 and the seat 88. When the tank housing 46 is removedfrom the base module 14, the projection 94 is removed from contact withthe head 96 of valve member. Therefore, the spring biases the valvedownwardly into the closed position thereby preventing the flow of fluidthrough the fluid aperture 862 to the fluid application system 950.

The fluid application system 950 conducts fluid from the fluid supplychamber 49 to fluid dispensing nozzles 100, which are mounted in thebrush housing 26 of the base module 14, and a fluid dispensing nozzle(not shown), which is mounted on an accessory cleaning tool (not shown),as best illustrated in FIG. 17. From the fluid supply chamber 49, cleanwater is conducted through conduit 140 to an inlet 332 to the mixingvalve assembly 310, which also includes a detergent inlet 336 that isfluidly connected to a detergent supply tank 870 by a conduit 314. Mixeddetergent and clean water form a solution that exits the mixing valveassembly 310 via an outlet 340, which is fluidly connected by a conduit142 to a pump priming system 280 disposed adjacent the pump 202. Aninlet port 282 for the pump priming system 280 is connected to theconduit 142, and pressurized fluid is expelled from the pump 202 througha pump outlet port 283, which is fluidly connected via a conduit 146 toa T-connector 150. The T-connector 150 supplies pressurized fluid toboth the accessory tool (not shown) and the heater 54 via conduits 148,138, respectively. The conduit 148 includes a grip valve 132 by whichthe user can manually displace a valve member, thereby enabling the flowof non-heated, pressurized fluid to the spray tip on the accessory tool.

The conduit 138 includes a trigger valve 134 having a displaceable valvemember actuable by a trigger assembly 430, as best shown in FIG. 4, forselectively supplying the in-line heater 54 with pressurized cleaningsolution. The trigger assembly 430 includes a switch 432 mountedconveniently within the closed loop grip 18 of the upright handleassembly 16, through which the user can depress the switch for actuatinga manual link 434 for displacing the valve member in the trigger valve134, thereby allowing fluid to flow to the inlet port 72 of the in-lineheater 54.

Heated while passing through the heater 54, the fluid exits the in-lineheater 54 via an outlet port 74, which is fluidly connected via aconduit 136 to an inlet 652 for a flow indicator 650. An outlet 654 forthe flow indicator is fluidly connected to a T-connector 156 via aconduit 134. The T-connector 156 supplies fluid dispensing nozzles 100,which are mounted in the brush housing 26 of the base module 14, andsupplied with heating cleaning solution via conduits 126, 128.

A detergent supply tank 870, as best illustrated in FIG. 3, is receivedwithin a well formed in the upper housing 19 of the base module 14. Thesupply tank 870 includes a top surface 872 shaped complimentary to theexterior of the upper housing 17. A bottom surface 874 of the supplytank 870, as best shown in FIG. 17, includes an aperture 876 surroundedby a threaded spout 878, which receives a mated threaded cap 880 havinga valve mechanism 882 therethrough. The valve mechanism 882 will not bedescribed here as its structure and function mimics that valve mechanism80 described above for the tank assembly 50, as it too seats on aprojection 94 in a valve seat 318 for displacing the valve mechanism882. The valve seat 318 of the mixing valve assembly 310 includes afluid reservoir 320 for receiving and conducting fluid to one end of anL-shaped conduit 314, the other end being mounted to a detergent inlet336 of the mixing valve assembly 310. The threaded cap 880 also includesan air return conduit 890 mounted therethrough for equalizing thepressure inside the detergent supply tank 870 with the outsideatmosphere.

The mixing valve assembly 310 is positioned intermediate the tankassembly 50 and the solution pump 202. Preferably, the mixing valve 310is a variable mixing valve to accommodate differing mixtures ofdetergent and clean water. As seen in FIGS. 10, 11 and 17, the variablemixing valve 310 comprises a valve body 330 having a clean water inlet332 that is fluidly connected to the fluid supply chamber 49 and adetergent inlet 336 that is fluidly connected to a detergent supply tank870 by the valve seat 318 and, via the fluid reservoir 320, the L-shapedconduit 314. The mixed solution outlet 340 is also formed on the valvebody 330 and is adapted to conduct the clean water and detergentmixture, i.e., the cleaning solution, from the mixing valve 310 to afluidly connected pump priming system 280 adjacent the inlet of the pump202.

The valve assembly 310 includes an end cap 344 mounting a coaxialplunger 350 in a central body portion 346. The end cap 344 partiallyreceives a thread 372 of a knob 374 such that the plunger 350 can beraised or lowered in the valve body 346 when the knob 374 is turned.

The plunger 350 includes an annular groove 356 formed in a distal end276 thereof. The groove 356 is received within an O-ring 358. The distalend 276 and O-ring 358 are adapted to create a fluid seal inside thecircular valve body 346 when the plunger 50 is in its lowermost portion,as shown in FIG. 11, and define a mixing chamber 360 when the plunger350 is raised from its lowermost position, as shown in FIG. 10.

The distal end 276 of the plunger 350 further includes a tapered groove364, which is tapered so that the groove has a greater cross-sectionalarea immediately adjacent the head end 276 than it does a distancespaced upwardly therefrom. The tapered groove is positioned in thedetergent inlet 336 opening to control the flow of detergenttherethrough. That is, the tapered groove 364 accommodates varying flowrates of detergent from the detergent supply 870, through the conduit318, and through the detergent inlet 336 into the valve body 346. Thelower the plunger 350 is seated in the inlet 336, the less the area ofexposure of the tapered groove 364 in the valve body 346, therebylimiting the flow of detergent thereto.

The control knob 374 is mounted on an outside wall of the upper housingof the extraction cleaner for controlling the water to detergent ratioin the cleaning solution delivered to the fluid application system 950.The control knob 374 is mounted adjacent the end cap 344 and includes athread 372 that is received in a groove 380 of the end cap 344, so thatturning the knob 374 lowers or raises the plunger 350 in the valve body346. In a first position shown in FIG. 10, with the plunger 350 extendedupwardly from the valve body 346, the maximum cross-sectional area ofthe tapered groove 364 is exposed to define an inlet aperture 382 intothe valve body 346. Therefore, the maximum amount of detergent will bedrawn into the valve body 346 to mix with clean water supplied via inlet332, and ultimately discharged to the pump assembly 280 and fluiddispensing nozzles 100. The other extreme position of the plunger 350lowers the tapered groove 364 from the mixing chamber 360 completely soif there is no aperture 382 and thus no fluid flow communication betweenthe detergent inlet 336 and the valve body 346. Therefore, only waterwill be directed to the pump assembly 280 and spray tips.

As should be evident, rotation of the threaded knob 374 will provide aninfinite number of detergent-to-water mixing ratios between the twoextremes described above. In the preferred embodiment, however, thehousing adjacent the knob 374 is marked with three concentrationindicators: The first indicator is a water only or “rinse” position;second, a maximum detergent-to-water mixing ratio where the taperedgroove 364 is fully exposed in the valve body 346; or third, a standardmixing ratio approximately halfway between the extremes describedpreviously. Of course, any variation of the indicated concentrationpositions can be employed by simply rotating the knob 374 to a positionbetween any two indicated positions. The extreme positions are definedby the shape of the length of the thread 372, which includes oppositeends defining a pair of extreme positions for limiting the rotation ofthe knob 374 relative the cap 344.

In use, the knob 374 is intended to be positioned at the standard mixingratio position for the vast majority of cleaning operations. When ahigh-traffic or heavily stained area is encountered, the knob 374 can berotated to the maximum detergent position. If a clean-water rinsingoperation is desired, then the knob 374 can be rotated to the water onlyposition.

As best illustrated in FIG. 17, the mix of detergent and water isdelivered via conduit 142 to the inlet port 282 for the pump primingsystem 280, which is disposed adjacent an inlet nose 288 of the pump202. Thus, in operation, the drive motor 196 is activated, therebyimparting rotation through the drive shaft 198 to the interim driveshaft 200, and the pump 202 is primed, as will be explained below.Rotation of the interim drive shaft 200 causes the pump 202 topressurize the fluid received from the fluid supply chamber 49, via themixing valve assembly 310 and priming assembly 280. Further, rotation ofthe interim drive shaft 200 causes the agitation brush 206 to rotate.Pressurized fluid flowing from a pump outlet port 283 is conducted tothe in-line heater 54, a flow indicator 650, and then a plurality ofconventional fluid dispensing nozzles 100 provided near the front of thebase module 14 adjacent the agitation brush 206. The pressurizedcleaning solution sprays down onto the surface to be cleaned in afan-shaped pattern extending substantially the entire width of the basemodule 14. A fluid outlet port 74 of the in-line heater 54 is alsofluidly connected to a conduit 144, which is integrated into theaccessory hose 22. Fluid flows through the conduit 144 to the accessoryhose cleaning tool (not shown) provided at the terminal end of the hose22. With this configuration, pressurized cleaning solution is availableon demand for both the accessory cleaning tool and the fluid dispensingnozzles 100.

Referring to FIGS. 2, 5 and 6, the drive shaft 198 of the drive motor196 is interconnected to the interim drive shaft 200 of the centrifugalsolution pump 202 by the stretch belt 204, which allows dry, high speedoperation and operates as a clutch during brush roll-jam conditions. Theinterim pump shaft 200 is interconnected to the rotatably mountedagitation brush 206 by the timing belt 208, which allows a slower, hightorque wet operation.

The interim pump drive shaft 200 functions as an interim drive providinga step down from the drive shaft 198 to the stretch belt 204 and thetiming belt 208 to the agitation brush 206. Because of the step downstructure, the drive motor 196 can be a high efficiency, high speedmotor (30,000 plus rpm), which is stepped down at the interim drive pumpshaft (approximately 12,000 rpm), and further stepped down at theagitation brush 206 (approximately 3,500 rpm).

The pump shaft 200 includes the pair of coaxial spaced-apart pulleys220, 222, as best seen in FIGS. 2, 8-9, for receiving each respectivebelt 204, 208, with a radially extending baffle 218 disposed between thepulleys so that the inwardly disposed stretch belt 204 is insulated fromthe wet environment in which the outwardly disposed timing belt 208operates to drive the agitation brush 206. A barrier coplanar with theradial baffle 218 insulates the environments from each other as formedby the juncture of a pair of belt access doors 250, 252, as will bedescribed below. The stretch belt 204 also functions as a clutch whenthe agitation brush 206 is jammed. Because the agitation brush 206 isconnected to the interim pump drive shaft, and the interim pump driveshaft 200 is connected to the motor drive shaft 198, there must be somemechanism to provide relief to the motor 196 when the agitation brush206 is jammed. This relief occurs at the drive shaft 198, which willturn inside the stretch belt 204 without rotating the stretch belt 204when the interim pump shaft 200 stalls due to an agitation brush 206jam.

As best shown in FIGS. 5-9, the timing belt 208 is structurally walledoff from the stretch belt 204 by the barrier defined in part by thefirst belt access door 250, second access door 252, and the baffle 218.Removing the first belt access door 250 provides access to the timingbelt 208 connecting the pump drive shaft 202 and the agitation brush206. Access to the stretch belt 204 connecting the motor drive shaft 198to the pump drive shaft 202 is provided only when the second belt accessdoor 252, disposed within a brush housing 26, is removed. As illustratedin FIG. 2, the first belt access door 250, having a substantiallyL-shaped cross-section, includes a substantially vertical portion 266and an angular, but substantially horizontal portion 264. As best shownin FIG. 9, the second belt access door 252 is rectangular, including anarcuate groove 254 in a front portion of a top surface 256 and atransversely extending arm 258 in a rear portion of the top surface. Thearm 258 secures the second door 252 in place in the brush housing 26 andsupports the pivot pin 462 on the pivot arm 460 of the floating brushassembly, as best shown in FIG. 5A.

More specifically, as shown in FIG. 2, the substantially verticalportion 266 of the first door 250 includes sides 240 that are receivedin a mated recess 242 surrounding an access aperture 236. Further, thefirst door 250 includes a depending flange 234 mounted to and spacedapart from a back portion of the door 250 and extending downwardlyparallel to the door 250 and further including an arcuate groove 244 ina lower end. Each side of the substantially horizontal portion 264includes a flexible tab 226 on each side that is received in arespective slot 228 disposed on the substantially horizontal face 222 ofthe upper housing 17 at each end of the access aperture 236 thatreceives the first belt access door 250. Thus, as the first belt accessdoor 250 is slid into place, the depending flange 234 extends behind theupper housing 17 defining the access aperture 236, the sides arereceived in grooves 242 in the upper housing 17 surrounding accessaperture 236, and the tabs 226 engage the slots 228 formed on thesubstantially horizontal portion 248 of the housing, whereby the firstaccess door 250 is secured in place. The first access door 250 can beremoved from the aperture 236 by flexing the tabs 226 inwardly torelease them from their receiving slots 228. As shown in FIG. 9, theinner depending flange 234, including groove 244, mates with theradially extending baffle 218 between the pulleys 220, 222 on the shaft200 and the arcuate groove 254 in the arm 258 of the second belt accessdoor 252 to separate the motor/pump stretch belt 204 from thepump/agitator timing belt 208.

The pump priming system 280 is disposed adjacent the pump inlet nose288, and draws from the fluid supply chamber 49 and the detergent tank870. The fluid supply chamber 49 is under negative pressure because itis in fluid communication with the recovery chamber 48 and the vacuumsource. Once primed, the pump 202 draws solution from the mixing valveassembly 310, and delivers the mixture to a spray tip 100 or anaccessory tool 44 for spraying on the surface to be cleaned. When thepump 202 stops, the solution in the supply conduit is drawn into thelow-pressure fluid supply chamber 49 and away from the pump 202. Acentrifugal pump is incapable of developing sufficient pressure to primeitself by overcoming the negative tank pressure.

With reference to FIG. 7, a pump priming assembly 280 as describedherein overcomes this problem. The pump-priming assembly 280, includes apriming chamber 260 for flooding the inlet nose 288 of the pump 202, aninlet port 282 for the chamber 260 that is fluidly connected to the nose288 of the pump 202, and a pump outlet port 283. A vacuum port 284 isfluidly connected to the vacuum source 40, or a portion of the recoverychamber 48 that is in fluid communication with the vacuum source 40.

The pump-priming assembly 280 also includes a hollow valve body 298having a plunger chamber 286 and a valve chamber 292. A valved opening295 joins the valve chamber 292 and the priming chamber 260. An outletopening 291 joins the valve chamber 292 and the plunger chamber 286.Also, an aperture 294 is formed at an upper inside-portion of the valvebody 298 to fluidly connect the valve body 298 and the outlet 284. Anelongate buoyant plunger 290 having a top portion 297 at one end and arubber umbrella valve 296 at the other is received for reciprocalmovement inside the valve body 298. More specifically, the umbrellavalve 296 reciprocates between the valved opening 295 and the outletopening 291 and within the valve chamber 292. Thus, the plunger chamber286 substantially houses the elongate plunger 290, while the valvechamber 292 houses the umbrella valve 296, which is coaxially attachedto the elongate plunger 290 for reciprocal axial movement therewith.

In operation, the pump 202 will be primed with fluid from the fluidsupply chamber 49 by activating the pump 202 and the vacuum motor 196,which will exert negative pressure on the vacuum outlet 284, therebydrawing any air out of the priming chamber 260 and plunger chamber 286,and further overcoming the negative pressure exerted on the fluid in theconduits 140, 142 connecting the fluid supply chamber 49 to the pump202. The air will be drawn through the valve body 298 into the vacuumimpeller fan housing 510. Preferably, the weight and dimension of theplunger 290 is coordinated with the amount of negative air pressureapplied to the pump priming assembly 280 from the vacuum source 40 sothat the negative air pressure applied to the plunger chamber 286 isinsufficient by itself to draw the plunger 290 upwardly and seal theoutlet opening 291.

As the vacuum motor operates to draw the air from the system, fluidfills the chamber 260 and enters the chambers 292, 286. Eventually, thefluid level will fill the valve chamber 292 and rise inside the plungerchamber 286, pushing the plunger 290 upwardly causing the umbrella valve296 to seal the outlet opening 291, thereby preventing water from risingfurther in the plunger chamber 286 and being sucked into the vacuumsource 40. Because the pump nose 288 is submersed at this point, waterenters the pump 202 and primes it. As the pump 202 sucks water from thepriming chamber 260, the plunger 290 is drawn downward in the plungerchamber 286, and the umbrella valve 296 descends therewith in the valvechamber 292 to activate a seal in the opposite direction, as theumbrella valve 296 seats in the valved opening 295. The reverse sealprevents air from being sucked into the priming chamber 260 from thefluidly connected chambers 292, 286. This cycle repeats each time atrigger 432 in the closed loop handle 18 is activated or the unit ispowered off and on again. Once the reverse seal has been established,the chamber 260 should remain filled, the nose 288 of the pump 202flooded, and, thus, the pump 202 sufficiently primed for normaloperation.

From the pump 202, the pressurized fluid flows through a conduit 146 toa T-connector 150 for supplying both floor nozzles 100 and an accessorytool 44. The T-connector 150 includes outlets 152, 154 for supplyingboth the in-line block heater 54, and a floor spray nozzle 64, or anaccessory cleaning tool 44, respectively. Specifically, the first outlet152 of the T-connector 150 is connected to fluid conduit 148 that isadapted to supply non-heated and pressurized cleaning solution to aspray nozzle (not shown) on an accessory cleaning tool (not shown)mounted at the terminal end of the accessory hose 22. The second outlet154 is fluidly connected via a conduit 138 to the in-line block heater54, shown best in FIG. 18.

The in-line block heater 54 receives pressurized cleaning solution fromthe pump 202, via the T-connector 150, and further has a heating element56 that is electrically connected to a source of electricity (notshown). As shown in FIG. 18, the heater 54 includes an aluminum body 84having an inlet port 72, an outlet port 74, a heating element 56disposed within the aluminum body 84, and a serpentine channel 78disposed on a top face 76 of the block heater 54. A cover 79, via agasket 70 seals the top face 76, and thus the channel 78, and fasteners86. The heating elements 56 located in the aluminum body 84 of the blockheater 54 uniformly heat the fluid as it passes through the channel 78across the block heater 54. The channel 78 includes an outlet port 74through which heated fluid exits the channel 78 to the conduit 136. Theheater 54 is mounted within the handle assembly 16 via shafts 71 andplugs 73 to bosses (not shown) in the handle assembly 16.

The size of the aluminum body 84 and the heating elements 56 areselected to effectively deliver approximately 500 watts of power to theheating block 54 to heat the cleaning fluid in the serpentine channel 78to a temperature of about 150-180° during the dry cycle of the cleanerand apply that heated cleaning fluid during the wet cycle, as will bedescribed more completely below. Use of approximately 500 watts of powerfor the heater 54 leaves sufficient power from a convention 120 voltpower line for the vacuum motor, agitation brush and pump while heatingthe solution to the target temperature with a minimal warm-up time ofapproximately one minute. To enhance this process, hot tap water(defined as approximately 110-120° Fahrenheit) can be dispensed into thereservoir from a household tap. The solution that passes through thein-line block heater 54 is heated approximately 30° to 35° to reach atarget temperature of approximately 150° Fahrenheit. A thermostaticcontroller is preferably mounted to a face of the heater 54 to limit theblock temperature to 180° F. The solution that passes to the upholsteryattachments does not get the temperature boost. A non-heated solution ispreferred for upholstery, which is more sensitive to heat damage.

Powered by approximately 500 watts, the in-line block heater 54 willboost the temperature of water 16° Fahrenheit on a continuous basis at850 milliliters a minute. Since an approximately 30° temperatureincrease is desired, it is necessary to store heat energy in thealuminum body 84 of the in-line heater block 54 during the dry cycle anddeliver it to the solution during the wet cycle. The recommendedcleaning process with the extraction cleaning machine 12 describedherein is two wet strokes, defined as movement of the extractioncleaning machine 12 while cleaning solution is sprayed from the nozzles100 to the carpet being cleaned, followed by two dry strokes, defined ascleaning solution and dirt removal through the suction action of thesuction nozzle 34. There is thus an opportunity to effectively deliver1000 watts of heat energy to the solution by storing 500 watts duringthe dry cycle. Furthermore, a typical cleaning stroke is about 10seconds maximum, so the heat reservoir must have the capacity to store500 watts for approximately 20 seconds, which equals approximately10,000 Joules of energy.

The heating element 56 is embedded into the aluminum body 84, which isof ample mass to store the energy at some temperature below the boilingpoint of water (212° Fahrenheit). The larger the mass of aluminum, thesmaller the differential temperature needs to be to store the requiredenergy. On the other hand, the larger the mass, the longer the initialheat-up period becomes. Thus, there is an optimal size of aluminum blockthat is calculated based on a thermostat shut-off point of 180°Fahrenheit. This block temperature keeps stagnant water from boiling andalso heats the solution that passes through the serpentine channels 78on the block face 76 to a temperature of approximately 150° Fahrenheitbefore leaving the in-line block heater 54 through outlet port 74.

In operation, when the heater 54 is initially energized electrically, itheats to its thermostatically controlled shut-off temperature inapproximately one minute. A thermostat 92 is included on a lower face108 of the body 84. During use, the cleaning solution passes through theheating channel 78 in the in-line block heater 54, drawing energy fromthe aluminum body 84 and from the heating element 56 embedded thereinadjacent the underside of the solution channel 78. The aluminum body 84cools somewhat during the 20 second cycle and reaches a temperatureslightly below its starting temperature. During the dry cycle, thealuminum body 84 is reheated to its previous temperature ofapproximately 180° Fahrenheit. The heated solution leaving the in-lineblock heater 54 is applied to the carpet after passing through theconduit 136 to the flow indicator 650, and the conduit 134 from theindicator 650 to the fluid dispensing nozzles 100, which are positionedbetween the agitation brush 206 and the suction nozzle 34.

The flow indicator 650 is placed in the fluid flow path to provide avisible indication of fluid flow to the fluid dispensing nozzles 100. Asshown in FIGS. 19 and 20, the flow indicator 650 is mounted to an upperend of the arm 651, which extends upwardly from the motor housing 500 inthe base module 14. An opening 653 in the upper housing portion 17receives the flow indicator 650 when that portion is mounted to thelower housing portion 15. Alternatively, the flow indicator 650 can bemounted to the handle assembly 16 in a position to be easily viewed bythe operator. The flow indicator 650 comprises a circular body 660having an inlet 652, outlet 654, and a clear lid 662 having a threadedlip 670. As seen in FIG. 20, the indicator body 660 preferably houses animpeller 664 superjacent a screen filter 666, both of which aresuperjacent the fluid inlet 652 and the fluid outlet 654. The fluidinlet 652 is near the periphery of the body 660 and the outlet 654 isdisposed centrally. The lid 662 has threads 670 on the outside of thebody 660.

The lid 662 is clear, preferably made from the transparent plastic, sothat the user can see the fluid flowing into the indicator 650 androtating the impeller 664. Alternatively, one or more articles, such asa ball or disk can be mounted within the indicator body 660 andsubjacent the lid 662, whereby the operator can determine if there isfluid flow by movement of the article. Further, while a body 660mounting an impeller 664 is the preferred flow indicator, other suitableindicators include a float ball, spring plunger, or gravity plunger.

A float ball-type flow indicator can include a flow conduit having aT-shaped portion having a transversely oriented tube extending from acylindrical body defining the fluid flow path. A ball or other articlecan be mounted at the junction of the transverse tube and cylindricalbody for reciprocation within the transverse tube. When fluid is flowingthrough the cylindrical body, the ball or article moves into thetransversely oriented tube, whereupon it is visible to the operator andindicates proper fluid flow.

A spring plunger-type flow indicator can include a light spring to biasa ball, plunger, or other article in a housing having a window visibleto the operator. With fluid flowing through the housing, the ball,plunger, or other article moves against the bias of the spring to becomevisible in the window, thereby indicating to the operator that fluid isflowing properly. Alternatively, the ball, plunger, or other article canalways be partially visible, and include portions corresponding toproper fluid flow, such as green for proper fluid flow and red for nofluid flow, whereby fluid flow causing movement of the ball, plunger, orother article against the spring bias would change the portion of theball, plunger, or other article visible to the operator through thewindow, thereby indicating proper fluid flow.

A gravity plunger-type flow indicator can include a housing having aball or other article mounted on a ramp adjacent a window. As fluidflows through the housing, the ball or other article is forced up theramp, whereby it is visible to the operator to indicate proper fluidflow. Alternatively, like that for the spring plunger, a portion of theball or other article previously not visible through the window can bevisible when fluid flows through the housing to indicate to the operatorthat fluid flow is proper.

After pressurized fluid leaves the in-line heater 54, it enters theinlet 652 of the flow indicator 650 under pressure, such that it causesthe impeller 664 to rotate in a clockwise direction as pictured in FIG.20. The fluid rotates the impeller 664 until it reaches the center ofthe body 660, where it is forced through the screen filter 666 andoutlet 654 by the continuous flow of pressurized fluid into the flowindicator body 660.

The screen filter 666 prevents any debris from exiting the flowindicator 650. Any debris trapped by the screen filter 666 remainsvisible to the operator through the lid 662. The operator can simplyclean the flow indicator 650 by removing the threaded lid 662 andlifting the screen filter 666 from within the body 660 for cleaning. Thescreen filter 666 preferably includes apertures defined by the screen ofa diameter smaller than the diameter a passageway through the spraynozzle 64. This is of particular importance if the spray nozzle is noteasily serviceable by the operator or a service provider. Further, whenusing an in-line heater 54, a screen filter 666 is a precaution againstplugging the passageway through the spray nozzle 64 from scales formingin the heater 54.

After the cleaning solution has been applied to the surface to becleaned via the spray nozzle 64, or multiple spray nozzles 64, the usedcleaning solution and entrapped dirt are removed from the surface beingcleaned through the suction nozzle 34, which opens into the firstworking air conduit 704 extending along the top of the base module 14between the upper housing portion 17 and the transparent facing 19, asbest shown in FIGS. 2, 12 and 13. The first working air conduit 704terminates at a junction 740 with the second working air conduit 706,which is defined by passageway communicating the vacuum source 40 withthe suction nozzle (not shown) on the distal end of the accessory hose22. With this configuration, the drive motor 196 creates the vacuumsource 40 that is applied to the surface being cleaned through eitherworking air conduit 704, 706.

The terminal end of the accessory hose 22 is secured to a hose mounting702 at a distal end of the accessory hose intake duct 540 partiallydefining the second working air conduit 706, which extends, in aU-shape, from the accessory hose 22, beneath the removable tank assembly50, and to the junction 740 with the working air conduit 704, as bestseen in FIGS. 2 and 12. A flapper valve 114 pivots at the junction 740,disposed in the base module 14, to alternatively close the first workingair conduit 704, between the suction nozzle 34 and the air/waterseparator lid 700, and the second working air conduit 706 between thehose mounting 702 and the air/water separator lid 700, as best shown inFIGS. 12 and 14. The valve 114 seats on a gasket 113 about the junction740. When the user is cleaning floors, the flapper valve 114 is inposition to direct all of the working air generated by the vacuum source40 to the suction nozzle 34. However, when the user desires to use theaccessory hose 22, the flapper valve 114 is pivoted to an accessory hoseposition, as shown in phantom lines in FIG. 12. In this position, theflapper valve 114 seals the working air conduit 704 and connects theaccessory hose 22 to the vacuum source 40. Regardless of whether themachine is operating for on-the-floor cleaning or accessory hosecleaning, all of the dirt and water recovered are directed into therecovery chamber 48.

An over-center diverter valve assembly 110 including a movable flappervalve 114 in the junction 740 between working air conduits 704, 706, andactuable by an actuator knob 180, on the extraction cleaner housingcontrols the diversion between the conduits 704, 706. More specifically,the actuator knob 180 to flapper valve 114 linkage assembly, as shownbest in FIGS. 12 and 13, includes an arm 160 attached at an upper end tothe flapper valve 114, which includes a transversely extending supportaxle 162, and at a lower end to a cup-shaped bearing 170 on the end of apiston 172. The support axle 162 is mounted for rotation in the junction740 between the working air conduits 704, 706, whereupon the valve canpivot between two extreme positions, as shown in FIG. 12. At a lowerend, the arm 160 ends in a transversely extending leg 164, which movesrelative the center of the actuator knob 180 depending on the positionof the actuator knob 180 when turned by the user.

The actuator knob 180 includes a handle 184, and a piston assembly 190on a back face. The piston assembly 190 includes piston housing 176,piston 172, and a compression spring 174. The piston 172 slidescoaxially in the housing 176, and is biased upwardly by the spring 174mounted therein. Specifically, the spring 174 biases the piston 172 outof an opening 196 in a top portion of a tubular piston housing 176.

When the actuator knob 180 is turned by the user, the lower leg 164moves closer or farther from the knob rotation axis, thereby increasingor decreasing the distance between the lower leg 164 and the axis. Asthis distance increases, the spring-biased piston 172 forces the lowerleg 164 upwardly. The arcuate path of the lower leg 164 as it travelsover the center of the knob axis rotation imparts rotation to theflapper valve 114 about the fixed support axle 162. The rotation is inresponse to the changed distance of the mounting of the piston assembly190 from the actuator knob 180 rotation center. As it moves away fromthe center, the piston 172 expands at an angle relative to the supportaxle 162. The lower leg 164 of the L-shaped arm 160 must rotate in thecup-shaped bearing 170 at the end of the piston 172 because the axle 162is fixed. Thus, the flapper valve 114 rotates in response to the angleof the joint between the expanded piston 172 and the lower leg 164 (notshown). Tabs formed on the back face of the knob 180 limit the rotationof the knob so as to effectively define two positions correlating to theopen conduit 704/closed conduit 706 position and the open conduit706/closed conduit 704 positions.

The diverter valve assembly 110 described above permits the uprightextraction cleaner fluid dispensing mechanism to be used as a pre-sprayapplicator. That is, by diverting the suction to the accessory hose 22,and applying solution through the fluid dispensing nozzles 100 adjacentthe agitation brush 206, the upright extraction cleaner 12 can be usedto dispense fluid and agitate the carpet without having the appliedsolution immediately extracted from the carpet through the suctionnozzle 34 adjacent the agitation brush 206 and fluid dispensing nozzles100. Thus, the fluid application system 950 remains operable regardlessof the position of the flapper valve 114.

As best seen in FIGS. 12-14, 14A and 14B, the working air conduit 704terminates at the junction 740 with the working air conduit 706. Thejunction 740 connects the selected conduit 704, 706 to a U-shaped inlet780 to the air/water separator lid 700, which is secured to the tankassembly 50 by the rotatable handle 790. Thus, from the U-shaped inlet780 to the air inlet 764, the air path entering the lid 700, as shown inFIG. 14, is substantially horizontal.

From the tank air inlet 764, the air/water/debris mixture is conductedinto a center portion of a tank lid separation chamber 750, where thecross sectional area is greater than the flow conduits 704, 706,junction 740, and inlets 780, 764 to slow down the velocity of the airstream for gravity separation of the air from the liquid, dirt anddebris. Because the lid 700 is formed of a transparent plastic material,the user can easily observe the dirt and water passing up through theintermediate flow conduit and the fluid level inside the tank assembly50.

The substantially rectangular chamber 750 is defined by a transparentlower portion 752 substantially surrounded on all sides by a transparentside wall integral with the underside of the air/water separation lid700. The chamber 750 is further defined upwardly by a transparent face756 of the lid 700. The air inlet opening 764 is disposed adjacent anair outlet opening 764. The underside of the face 756 further includes acircular downwardly extending shroud 770 adapted to surround in part theopen flexible bladder filling spout 124, which is retained by the baffleplate 800 and positioned adjacent the separation chamber 750.

The working air flow enters the hollow interior of the separationchamber 750 via the air and water inlet 764 and passes horizontallybeneath the transparent face 756 to a rear wall defining a firstdiverter baffle 755 at which it is redirected 180° forwardly through anopening 751 to a rectangular, extended outlet passage 757 formed in alower, intermediately disposed portion of the bottom wall 752 at whichit is again redirected 180° by a second diverter baffle 759 defined by afront wall disposed forward, transverse, and beneath the opening 751.The air flow then exits the separation chamber 750 through an inletoutlet 760, whose position is dictated by tank geometry, as thepreferred position is a “dead spot” in tank air flow to maximizeair/water separation. From here, the water is directed into the interiorof the tank between the 750 and the baffle 800, and away from theseparation chamber 750 to the air exit 762. It is significant that allair/water separation occurs above the baffle plate 800, thus minimizinginterference with the recovered water (i.e., no foaming) in the areadisposed below the baffle plate 800. This characteristic is necessitatedby the inclusion of a flexible bladder disposed in the tank recoverychamber.

In summary, air and water enters the inlet 764, from where it ischanneled to the air/water separation chamber 750 in which it strikesthe first diverter baffle 755, is redirected approximately 180° andthrough the opening 751 to the outlet passage 757, where it is againredirected approximately 180° by second diverter baffle 759, and thenpasses into the interior of the recovery chamber 48. The multiplechanges in direction as well as the expansion in volume in theseparation chamber 750 facilitate the separation of water and debrisfrom the air. As best seen in FIG. 14, the air, free of water anddebris, exits the tank via rectangular outlet 762, and traverses ahorizontal conduit 774 to a vertical exit conduit 776, which is disposedadjacent the horizontal inlet 780 leading air into the separation lid700 via air inlet opening 764. Thus, the air inlet 780 and air exitconduit 776 are vertically adjacent. The air exit conduit 776 feeds thevacuum intake duct 530, which is connected to the vacuum source 40, asbest seen in FIGS. 2 and 14.

As best shown in FIG. 3, a fluid containment baffle 800 is mountedinside the hollow interior of the tank assembly 50 immediately below theseparation lid 700, and is intended to prevent the excessive sloshing ofthe recovered dirt and liquid and also contain any foam generated insidethe tank assembly 50. The planar baffle 800 comprises a flat body 810mated to snap fit within the tank housing 46. Further, apertures 820 areformed through the plate 800 for receiving the recovered fluid into therecovery chamber 48 of the tank assembly 50. A circular aperture 826retains the bladder filling spout 124 in position by preventing it fromfloating upwardly in the tank and further locking the bladder in placewhile giving it mechanical support.

The baffle plate 800 is snapped into place by retainers 830 that arereceived on tabs 836 formed on the interior of tank housing 46 to securethe baffle plate 800 in the tank assembly 50. The apertures arecentrally mounted in the baffle plate 800 to prevent air movement, whilefacilitating fluid and debris deposits, into a lower portion of tankassembly 50 so that the recovered fluid remains undisturbed. Further,the baffle plate 800 is closed at the edges to prevent sloshing of therecovered fluid into an upper portion of the tank assembly 50 duringmovement of the cleaning machine 12

As shown best in FIGS. 14 and 14A, a float assembly 900 extends throughthe baffle plate 800 for moving an integral door across the exit port ofthe tank to prevent recovered solution from entering the tank exhaust inan overfill condition. As best shown in FIG. 3, the flag-shaped floatassembly 900 comprises a buoyant base 902 and a closure plate 904interconnected to one another by a support plate 906. The closure plate904 is dimensioned to fully seal an exit to the tank to preventrecovered solution from entering the tank exhaust in an overfillcondition. The closure plate 904 further includes a pair of triangularprojections 905 extending transversely from a substantially verticalfront face. The front face engages the wall 768 defining the air exit762 from the tank, and the projections 905 cam along that wall 768 toprevent premature and partial closing of the exit 762 as the plate 904is drawn against the exit by the suction therethrough.

The float assembly 900 is limited primarily to vertical movement withrespect to the tank assembly 50, with the closure plate 904 positionedabove the fluid containment baffle 800 and the buoyant base 902positioned below the baffle 800. A narrow slot 920 is provided in afront portion of the baffle 800 through which the support plate 906 ofthe float extends. Further, a housing 910 secured to the interior of thetank housing 46 guides the buoyant base, and thus the float assembly900, in a vertical direction. In the assembled position, the closureplate 904 is positioned above the baffle 800 and the buoyant base 902 ispositioned below the baffle 800.

As the recovered fluid within the tank assembly 50 rises, the floatassembly 900 will also rise until, eventually, the closure plate 904nears the tank exhaust exit opening, at which point the closure plate904 is sufficiently drawn against the exit 762 opening by the suctionfrom the vacuum motor to close the airflow therethrough. As discussedabove and illustrated in FIG. 14A, the triangular projection 905extending from the front face 907 ensure the closure plate is not drawnagainst the exit 762 prematurely, which would result in a partialclosure of the opening. Rather, the projections 905 ride the housingdefining the opening until drawn into total closure of the exit 762.Once this happens, the pitch of the operating vacuum changessufficiently to warn the user that the fluid recovery chamber 48 is fulland must be emptied.

As best shown in FIG. 3, a drain plug 850 seals an aperture through awall in a lower portion of the rigid housing 46 of the tank assembly 50through which recovered fluid can be removed without tipping the tankassembly 50, and also through which the tank assembly 50 can be cleanedby flow-through rinsing. More specifically, a rounded wall of the rigidtank housing 46 includes the drain plug 850 mounted in an aperture 854.A bottom portion of the aperture 854 is substantially planar with abottom wall 860 of the tank housing 46. Thus, any recovered fluid willflow through the aperture 854 when the drain plug 850 is removedtherefrom. Further, the tank assembly 50 can be cleaned without havingto tip the tank assembly 50 since the drain plug 850 can be removed forflow-through rinsing. This feature is particularly important because theflexible bladder 120 defining the fluid supply chamber 49 remains inplace while the recovered fluid is drained from the recovery chamber 48.The drain plug 850 eases cleaning of both the interior of the rigidhousing 46 and the exterior of the flexible bladder 120.

As best shown in FIGS. 21 and 22, the drain plug 850 comprises a knob851 extending through a circular washer 856 which mounts two resilientlegs 853. The resilient legs 853 are located diametrically on a lowerface of the washer 856 and comprise, on an outer face of each leg 853,an upper ridged protrusion 857 and a lower ridged protrusion 858. Thelower ridged protrusion 857 is rounded so that it forms a detentmechanism with the opening in the tank wall. The upper ridged protrusion857 has a slanted outer surface so that the legs are resilientlydeflected as the drain plug is installed into the aperture 854, and hasa sharp return inner surface so that the return inner surface will bearagainst the inner surface of the wall of the tank housing as the drainplug 850 is pulled outwardly of the tank. Thus, the drain plug is easilyinstalled into the aperture 854, but is retained therein by the innersurface when the plug is removed from the aperture 854 for draining thetank. In the normal, closed position of the drain plug 850, the lowerface of the washer 856 abuts the rear wall of the tank housing 46. Thedrain plug further has a pair of retaining flanges 859 which fit behindthe wall of the tank adjacent the aperture 854. To this end the aperturehas indented slots to receive the flanges 859. The To drain fluidthrough the aperture 854, the drain plug 850 is rotated a quarter turncounterclockwise and pulled toward the rear of the upright extractioncleaning machine 12 a suitable distance such that the upper ridgedprotrusion 857 of the resilient legs 853 moves past the rear wall of thetank housing 46 and the lower ridged protrusion 858 of the resilientlegs 853 abuts the inner wall of the tank housing 46. The diameter ofthe aperture 854 is less than the normal distance between the resilientlegs 853 so that the legs 853 are pressed inwardly and thereby preventthe drain plug 850 from separating from the tank housing 46. The drainplug 850 is restored to its normal, closed position by pressing thedrain plug 850 toward the front of the upright extraction cleaningmachine 12 to cause the washer 856 to abut the rear of the tank housing46 and turning the drain plug 850 one-quarter turn clockwise.

In use, the operator removes the tank assembly 50 from the well 36 inthe base module 14, and further removes the lid 750 from the tankhousing 46 to expose the open filling spout 124 of the flexible bladder120, whereupon the bladder 120 can be filled with water from a sourcesuch as a household tap. Next, the user replaces the lid 750 and swingsthe handle 790 upwardly to seal the lid 750 to the tank housing 46,whereupon the tank assembly 50 can be carried to the well 36 of the basemodule 14 and replaced therein for use. Upon replacement, the valvemember 82 in the valve mechanism 80 mounted in the bottom surface 862 ofthe tank housing 46 is displaced by the projection 94 in the valve seat88, whereupon the clean water in the fluid supply chamber 49 is in fluidcommunication with the fluid application system 950. The detergentsupply tank 870 is removed from its well 884, and then its cap 880 isremoved so that the tank 870 can be filled with concentrated detergent.Once the supply tank 870 is filled and the cap 880 is replaced thereon,the supply tank 870 is replaced in its well 884, whereupon its valvemechanism 882 permits the flow of concentrated detergent through theconduit 318 to the mixing valve assembly 310.

The extraction cleaning machine 12 can then be powered by activating anmain power switch 534 disposed on the handle assembly 16, whereby themotor 196 is activated, and the vacuum source 40 for the working airflow conduits 704, 708 are operable. Further, the heater 54 isseparately operable by a heater power switch 536 when the main powerswitch 534 is in the “on” position. The user then supplies pressurizedcleaning solution to the agitation brush 206 by depressing the switch432 in the closed loop grip 18, whereupon solution flows to and throughthe fluid dispensing nozzles 100. As the user applies cleaning fluid andagitates the surface being cleaned with the brush 206, the user pushesthe cleaning machine 12 forward and rearward, with the forward strokesbeing defined as wet cycles and the rearward strokes being defined asdry cycles. During the wet cycles, the cleaning solution is applied tothe surface via the fluid dispensing nozzles 100 and the agitation brush206 scrubs the subjacent surface. During the dry cycles, the suctionnozzle 34 removes applied solution, as well as dirt and debris, from thesurface being cleaned and carries it to the recovery chamber 49 via theworking air conduit 704.

The cleaning machine 12 can also be used as a pre-spray applicator andagitator by simply diverting the air from working air conduit 704 to theworking air conduit 708, which connects the vacuum source 40 to theaccessory hose 22. In this use, the accessory hose 22 functions solelyas a bypass aperture for the working air supplied by the vacuum source40. Thus, fluid is applied via the fluid dispensing nozzles 100 andagitated into the surface being cleaned by the brush 206, but there isno suction at the suction nozzle 34, and thus no dry cycle. When thesolution has been adequately applied and the surface adequatelyagitated, the user can divert suction back to the working air conduit704, whereupon the applied solution and other debris can be removed fromthe surface without application of solution, which is controlled by theuser through trigger 432.

To use the accessory cleaning tool (not shown), the user diverts workingair flow from the conduit 704 to the conduit 708, whereupon theaccessory hose 22 is fluidly connected to the vacuum source 40.Furthermore, the user can apply pressurized cleaning fluid to thesurface to be cleaned by pressing the grip valve 132 on the accessorycleaning tool. In sum, cleaning solution can be applied by actuating thegrip valve 132 and removed via the suction nozzle (not shown) incommunication with the vacuum source 40 via the working conduit 708.Also, the accessory tool may further include an agitation brush drivenby an impeller that is driven by ambient air drawn through an aperturedistinct from the suction nozzle in the accessory tool, but towards thesame vacuum source 40.

Once the surfaces have been cleaned, or the recovery chamber 48 hasbecome filled and the float assembly 900 has blocked the air exit 762from the air/water separator lid 750, power to the cleaning machine 12is turned off and the tank assembly 50 is removed from the well in thebase module 14 and carried by its handle 790, which seals the lid 750 tothe tank housing 46, and carried to a point of disposal, such as a sinkdrain, whereupon the contents of the recovery chamber 48 can be emptiedby removing the drain plug 850 from the aperture 854 through wall 852.Once removed, the contents of the recovery chamber 48 flow through theaperture 854. Furthermore, the tank assembly 50 can be rinsed with cleanwater, which also flows through the aperture 854 in the wall 852 of thetank housing 46.

While particular embodiments of the invention have been shown, it willbe understood, of course, that the invention is not limited theretosince modifications may be made by those skilled in the art,particularly in light of the foregoing teachings. Reasonable variationand modification are possible within the scope of the foregoingdisclosure of the invention without departing from the spirit of theinvention.

What is claimed is:
 1. A portable surface cleaning apparatus,comprising: a housing adapted for movement along a surface to becleaned; a liquid dispensing system mounted to the housing andcomprising: a liquid dispenser for applying liquid to the surface to becleaned; a liquid supply tank for holding a supply of cleaning liquid; aliquid supply conduit fluidly connected to the liquid supply tank and tothe dispenser for supplying liquid to the dispenser; a liquid recoverysystem mounted to the housing and comprising: a recovery tank removablymounted in the housing and having a liquid recovery chamber for holdingrecovered liquid, the recovery tank further having an inlet opening; asuction nozzle at a front portion of the housing, forwardly of therecovery tank and adapted to draw dirty liquid from the surface to becleaned; a first working air conduit extending rearwardly from thesuction nozzle to an inlet opening to the recovery chamber; an accessoryhose mounted at one end to a rear portion of the housing behind therecovery tank for optional above floor cleaning; a second working airconduit connected at a first end to the accessory hose one end and, atanother end forwardly of the recovery tank, connected to the inletopening to the recovery chamber, the second working air conduit beingformed of a unitary duct; a vacuum source in fluid communication withthe recovery chamber for generating a flow working air from the nozzleand the accessory hose through the first and second working air conduitsand through the recovery chamber to thereby draw dirty liquid from thesurface to be cleaned through the nozzle and accessory hose and thefirst and second working air conduits, and into the recovery chamber tothereby recover dirty liquid from the surfaces to be cleaned; and aconversion valve mounted between the first and second working airconduits and the inlet to the recovery chamber to selectively connectthe vacuum source to either the suction nozzle or to the accessory hose.2. The portable surface cleaning apparatus according to claim 1 whereinportions of the unitary duct that extend beneath the recovery tank areflat.
 3. The portable surface cleaning apparatus according to claim 1wherein at least one of upper and lower portions of the unitary duct isflat.
 4. The portable surface cleaning apparatus according to claim 1wherein the housing includes a base housing and an upright handle andthe upright handle is pivotally mounted to the base housing.
 5. Theportable surface cleaning apparatus according to claim 4 wherein therecovery tank is removably mounted in the base housing.
 6. A portablesurface cleaning apparatus according to claim 1 wherein the secondworking air conduit is U-shaped and extends directly below the recoverytank.
 7. A portable surface cleaning apparatus, comprising: a housingadapted for movement along a surface to be cleaned; a liquid dispensingstem mounted to the housing comprising: a liquid dispenser for applyingliquid to the surface to be cleaned; a liquid supply tank for holding asupply of cleaning liquid; a liquid supply conduit fluidly connected tothe liquid supply tank and to the dispenser for supplying liquid to thedispenser; a liquid recovery system mounted to the housing andcomprising: a recovery tank removably mounted in the housing and havinga liquid recovery chamber for holding recovered liquid, the recoverytank further having an inlet opening; a suction nozzle at a frontportion of the housing, forwardly of the recovery tank and adapted todraw dirty liquid from the surface to be cleaned; a first working airconduit extending rearwardly from the suction nozzle to an inlet openingto the recovery chamber; an accessory hose mounted at one end to a rearportion of the housing behind the recovery tank for optional above floorcleaning; a second working air conduit connected at a first end to theaccessory hose one end and, at another end, connected to the inletopening to the recovery chamber, the second working air conduit having acentral portion that lies directly beneath the recovery tank; a vacuumsource in fluid communication with the recovery chamber for generatingflow of working air from the nozzle and the accessory hose through thefirs and second working air conduits and through the recovery chamber tothereby draw dirty liquid from the surface to be cleaned through thenozzle and accessory hose and the first and second working air conduits,and into the recovery chamber to thereby recover dirty liquid from thesurfaces to be cleaned; and a conversion valve mounted between the firstand second working air conduits and the inlet opening to the recoverychamber to selectively connect the vacuum source to either the suctionnozzle or to the necessary hose.
 8. A portable source cleaning apparatusaccording to claim 7 wherein the central portion of the second workingair conduit has a relatively flat upper portion.
 9. A portable surfacecleaning apparatus according to claim 8 wherein the second working airconduit is formed of a unitary duct.
 10. A portable surface cleaningapparatus according to claim 9 wherein the second working air conduit isU-shaped.
 11. A portable surface cleaning apparatus according to claim 7wherein the second working air conduit is U-shaped.